Variable-voltage transformer.



-' No. 890,730. PATENTED JUNE 16, 1908.

M. O. TROY.

VARIABLE VOLTAGE TRANSFORMER.

APPLICATION FILED JULY 26, 1906. RENEWED FEB. 5, 1908- 2 SHEETS-SHEET 1.

%m Matthew 0. Troy I Z @WZWJ UNITED srarnsg grnnr onmon.

lVlr-XTTHE\\' O. TROY, OF SCHEXECTADY, XlCW YORK. A SSIGNUl-l TL) GEN ERAL ELECTRIC COMPANY, A CORPOlt-VFIOX OF NEW YORK.

VARIABLE-VOLTAGE TRANSFORMER.

Application filed July 26, 1906, Serial No. 327,877

To all whom itmay concern:

Be it known that l, MATTHEW O. TROY, a citizen of the United States, residing'at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Variable-Voltage Transformers, of which the following is a specification.

My invention relates tovarialjde-voltage transformers of the type described in mv former applicatiom-8erial No.'292,906, filed December22, 1905, and its object is to 'p10. vide a transformer of this type having certain novel and useful features. In my former application I described a variabl-yol Cr transformer having a magnetic core will primary and secondary coils and two magnetic movable members, one arranged to vary the reluctance of the magnetic circuit, passing through both coils, and the other to vary the reluctance of the magnetic circuit shunting the secondary coil. In the arrangement of my former application both members were rectilinearly movable.

One feature of my present invention consistsin pivotally mounting one of \the two movable members. This arrangement ren ders it possible with a simple n1echani,cal construction to obtain any desired relative rates of movement of the two members so as to obtain a more uniform graduation of the secondary voltage.

A second feature of my invention consists in moving the secondary coil as W ll as the magnetic members 01",, core portio1 s. This feature is particularly,- valuable where it is desired to reduce the indu ced secondary voltage entirely to zeron I have found" that when only portions ofXthe core are moved a certain leakage flux still passes through the secondary coil when thd core portions are in position of minimum secondary voltage. By moving the secondary," oil, entirely away from the influence of tle primary coil the secondary induced voltageunay be reduced entirely to zero.

My invention will best be understood by reference to the accompanying drawings, in which 'f Figure l is a side elevation of a transformer,

arranged in accordance with my invention;

Fig. 2 shows a lan view of the same; Fig. 3

' shows a side e evation of a modification in Specification of Letters Patent.

core, which is E-sliaped, as clearly shownin Fig. 2, with. the primary coil B andthe second ary coil C spaced apart on its central member.

D represents a movable portion of the core, which pivoted at (Z and arranged by its movementto open and close the magnetic circuit between the ends of the three parallel members of the stationary core A, so as to vary the reluctance of the magnetic circui passingtln'eugh the primary and secondary coils.

E represents second movable magnetic member,-which is similar in construction to the member D,'but which is rectilinearly movable between the coils B and C. the member E is in its highest position above the core A, it has little effect upon the flux in core A, but when it is lowered to the posi tion shown in Fig. 1, it makes an effective flux shunt for the secondary coil, closinga magnetic circuit around the primary coil alone. Members D a. d E are simultaneously movable to reduce the induced secondary voltage. Member I) is moved outward to the positions shown in Figs. L and 2,*thereby opening the magnetic circuit threading both )rimary and secondary coils, while member *1 is moved to its lowest position, as shown stantially closed circuit forthe flux of the primary coil.

For operating members I) and E a shaft F is provided with a hand-wheelf. This shaft is connected by the crank G and a connecting rod g to member 1), and by thegear H and rack hto member E. With this arrangement it will be seen that the rate of move ment of the member E bears a 'lixcd relation to the rate of movement of the shaft F, while the rate of movement of member 1) varies according to the'position of the crank G. Thus, by properly positioning the crank on the shaft the, relative rates of movement of mem bers D and E may be made anything desired, so' as' to obtain a uniform variation of the secondary induced voltage with a given movement of shaft F.

small electromotive force in the secondary Referring first to Figs. 1 and .2, Arepresents the stationary portion of the magnetic hen j in Figs. 1 and 2; thereby aifording asub ltl-will be seen that even with the members 1 Patented June 16, 1908. 2

. Renewed. February 5, 1908. Serial No. 414,449.

loo

coil If it'is desired to reduce the secondary lnduced voltage wholly to Zero, the ar- 'rangement shown in Figs. and 4 may be employed. In these figures the secondary c011 C 1s mounted on and movable with the pivoted. member D, so that in the position of, mlmmum induced voltage the 0011 C 18 carried partly orwvholly outside of the ore A. Aside from the change in the mounting of the secondary coil C, the arrangement shown in Figs. Sand 4 isthe same as that already shown for Figs. 1' and 2.

v I do not desire tolimit myself to the particular construction and arrangement of parts here shown, but aim in the appended claims to cover all modifications which are moving said core within the scope of my invention.

-What I claim as new and desire to secure by Letters'Patent of th Tlnitedstates, is,

1. In avariable-voltage transformer, a magnetic core, primary and secondary CO1lS .spaced apart on said core, said core having a p1votally-mounted portion adapted to openby'its movement the magnetic circuit threading both coils, and a rectilinearly-movable magnetic member between said coils adapted by its movement to shunt the primary flux.

away from the secondary coil. 2. In a var1able-voltage transformer, 'a magnetic core, primary and secondary coils spaced apart on said core, said core having a pivotally-mounted portion adapted to open "by its movement the magnetic-circuit thread ing both coils, a rectilinearly-movable magnetic member between said coils adapted. by its movement to shunt the primary flux away from the secondary coil, and means for portion and said member simultaneously I magnetic core, primary and secondary c" spaced apart on said core, said core having a pivotally mounted portion adapted to open 3. In a variabie-voltage transformer seogso,

4;. In a variable-voltage transformer, a

magnetic core, primary and secondary coils spacedapart on said core, said. core having a pivotally-mounted portion adapted to open by its movement the magnetic circuit threading both coils, a rectilinearly-movable mag-- netic member between said coils adapted by its movement to rshunt the primary flux away from the secondary coil, anoperating shaft, a crank on said shaftconnected to said-core portion, and gear on said shaft connected to said member;

5. In a variable 'voltage transformer, a magnetic core, primary and secondary coils spaced aparton said core, two movable mag netic members arranged to vary the reluct'ances respectively of the magnetic circuit of the seconda-i'y coil and of a magnetic circuit shunting said coil, one of said members being pivotally mounted and the other rectilinearlymovable, and operating means mechanio' lly connected to both In mbers.

6. In a variable foltage transformer, a magnetic core,'pn'mary and secondary coils spaced apart on said core, said core hav g a pivotally-mounted portion adapted to .pen

by its movement the magnetic circuit threading both coils, the secondary. coil being so:

cured to and carried by said core portion, and

a rectilinearly-movable magnetic member adapted by its movement to shunt the primary flux away from the secondary coil.

7. In a variable-voltage transformer, a magnetic core, primary and secondary coils spaced. apart on said core, said corehaving' a: pivotally-mountedportion adapted by its movement to open the magnetic circuit threading both coils, the secondary coil being secured to and carried by said core portion, a

rectilinearly-1novable magnetic member adapted by its movement to shunt the pri.

mary :duX away from the secondary coil, and operating means mechanically connected to both said core portion and said member.

In witness'whereiii, I have hereunto set 11 hand this 25th sf July, 1906.-

IiATTHEVV O. TRQY.

Witnesses BENJA IN 5%, HULL, GRACE M. IANIGAN. 

